Scouting is a means of gaining information instead of or in conjunction with Lookamancers.
When scouting, a stack, generally, but not necessarily, consisting of a single unit, moves through hexes beyond the vision of a larger force, or outside the area controlled by a side's cities.
A scouting unit is generally posessed of a high Move, is cheap (and therefore expendable), or, ideally, both.
The Royal Crown Coalition used both Marbits and Doombats to scout, in tunnels and the open field, respectively.
Jillian Zamussels and her gwiffons performed scouting duties in addition to attacking targets of opportunity.
To be of use, a scouting unit must have a means of conveying the information it gathers to its superiors.
Some methods used:
Thinkagram, as offered by Charlie's archons
Vinny Doombats can see directly through the eyes of any Doombat. It is unclear whether this ability is unique to him, or if some or all Transylvito Vampires can do this.
Barring all of these, messages can be hand delivered by troops with the Move available to reach their Commander